Mobtise-latch jfob jjoors



RHODOLPHS -KINSEER OF SPRINGFIELD, MASSACHUSETTS.

MORTIS'E-LATCH YIUOORS.

v"Speccaltion:oflletters .Patent No. 4,402, :dated `March .7, v1846.

To all 'whom t may conce/m'.-

Be it vvknown 'that LI, fRHoDoLrHUs K1Ns LEY, of Springfield, in thecounty of Hampden and State of Massachusetts, lhave -invented new anduseful Improvements in Mortise Door-Latches, and that `the following isa full, clear, and exact description of the principle or characterthereof which distinguishes them from all other things before known andof the manner of making, constructing, and using the same, referencebeing hfad to the accompanying drawings, making part of thisspecification, in which- Figure l is a perspective view of the latch;Fig. 2, a cross section of the same let into the mortise in the door;Fig. 8, a view of the latch with the cap of the case removed, and Fig.4, a longitudinal section inv the plane of the axis of the tumbler.

The same letters indicate like parts in all the gures.

In making mortise latches much diiiculty has been experienced in givinga form to the case to suit thin doors, and at ,the same time adapted tothe reception andworking of the mechanism, and the tting of a mortisemade entirely by boring to avoid the labor of mortising with a chisel.This end has been sought by substituting the cylindrical for the squareform; but to adapt this to the reception of a properly formed tumblerrequires too great a diameter to suit a medium thickness or thin doors.But by one of my improvements I attain this desideratum by forming thecross section of the case of three circles, one in the middle, to formthe thickness, of the case, and two small ones, one on each side of andbisecting the middle one to form the width ofthe case, so that a holeformed by boring one large hole and two small ones lwill receive thelatch case, the diameter of the large one being sufficient to give tothe axle of the tumbler the required length, and the two small onesgiving suiiicient width for the working of the levers of the tumbler andthe wings of the latch bolt on which the tumbler acts to operate it.

My second improvement consists in so locating the helical spring, whichprotrudes the bolt within a recess therein as to have one portion of itrest on a anch connecting the two sides of the bolt, and the other `endon a shoulder of the stud against which the permanent end of the springrests, by means of which arrangement much of the friction,

and consequent wear of the spring against the ca se is avoided.

fIn fthe accompanying drawings (a) represents 'the case the vform ofwhich is composed, AAas above fstated of three circles the center one to`form ythe thickness, and (c, o) the two side ones of smaller diameter,and forming, with the middle one, the width of the case, the centers ofthe two small ones being on or near the circumference of the large one,and the centers of all of them in the same plane. The part (a), whichforms the cap, being made separate from and connected with the rest by a4single screw (d). The journals of the tumbler (e) are fitted to andturn in appropriate boxes made i`n the case and cap, as clearlyindicated in the drawings: and the body of the tumbler lies in anelongated hole (f) in the rear end of the bolt (g), the sides thereofsliding in the recesses of the case made within the two small circles.The wings (7L 71,) project from thebody of the tumbler on a linetangential to a circle of less diameter than' the body thereof, so as toavoid the tendency to push out the bolt when acting against theshoulders (i, z') of the latch bolt to draw it back. `Tl`1e helicalspring that protracts the bolt lies in a recess (la) in the bodythereof, one end resting against the forward end of the recess andresting on d the flanch or plate (Z), connecting the two sides of thebolt, and against a stud pin` (m) attached to a bolt provided with ashoulder on which the other end of the helical spring rests, so thatduring the play of the bolt, the spring instead of making frictionthroughout its length rests only on the flanch or plate (Z) which movingwith it avoids much of the friction and wear.

From the foregoing description and examination of the drawings it willbe perceived that when the case is let into the door the whole strain onthe wood of the door'is along the surface of the small circles andnear'to their junction with the large one,

thus leaving a much greater thickness and ter, (the square) thethickness of the Whole case would be equal to the diameter of the largecircle, so that the strain Would of course come on the Wood at thecorners of` herein described to leave greater strength in the Wood ofthe door on eachside as specified, and to admit of fitting into the doorby boring simply. y

2. I also claim locating the helical spring in a recess in the body ofthe latch bolt in combination With the Inode of preventing friction andWearby sustaining one end on a flanch or plate of the bolt and ashoulder on the standard, as herein fully explained.

A RHODOLPHUS KINSLEY.

i Vitnesses:

A. P. BROWNE, J. J. GREENoUGi-L

